Improvement in illuminating vault-covers



UNITED STATES thereof, reference'being had to the accompa- PATENT OFFICE.

THADDEUS IIYATT, OF NEIV YORK, N. I, ASSIGN It TO ELIZABETH A. ll. HYATT, OF SAME PLACE.

IMPROVEMENT IN lLLUMlNATING VAULT-COVERS.

Specification forming part of Letters Patent No. 145.188, dated December 2, 1873; application filed October 22, 1873.

CASE 3.

To all whom it may concern: I

Be it known that I, THADDEUS llrn'r'r, of 1 New York, in the county of New York and in the State of New York, have invented certain new and useful Improvements in Illuminating Gratings; and do hereby declare that the following is a full, clear, and exact description nying drawing making a part of this specification, in which Figure 1 is a perspective view of my improved lens and fasteningnut separated, and Fig. 2 is a vertical central sect-ion of the same as applied to a plate.

Letters of like name and kind refer to like parts in each of the figures.

. My invention relates to the securing glass lenses in place within a metal grating; and it consists, principally, ina button-head glass lens provided with a threaded shank, and combined with a grating by means of a nut engaging with said shank, substantially as and for the purpose hereinafter specified. It consists, further, in a nut having its threaded central portion extended beyond its bearing face, substantially as and for the purpose hereinafter shown.

I11 the annexed drawing, A represents a glass lens, having an enlarged or button head, a, and a smaller shank, a, upon the latter of which is formed a screw-thread. The lens thus formed is placed upon a metal plate, 13, with its shank passing through a suitable opening in said plate, and its head resting upon the upper side of the same, in which position said lens is secured by means of a nut, (J, that is fitted from beneath over said threaded shank, and is secured upward against the lower side of said plate.

For use with plates having a thickness nearly equal to the length of the threaded neck, the nut O is formed of sheet metal, and has its threaded portion extended upward beyond its bearing-face, said extended portion being intended to pass into the opening that receives said lens, topermit which said opening is made somewhat larger than would otherwise be required.

The lens thus constructed is easily and quickly combined with or removed from its grating, thus enabling the light-openings to be used for the purpose of ventilation.

Having thus fully set forth the nature and merits of my invention, what I claim as new 1s- 1. A button-head glass lens provided with a threaded shank, and combined with a grating by means of a nut, substantially as and for the purpose specified.

2. A nut having its threaded central portion extended beyond its bearing-face, substantiall y as and for the purpose shown.

In testimony that I claim the foregoing I have hereunto set my hand this 26th day of July, 1873.

THADDEUS HYAIT. lVitnesscs:

AMBRosn MoNnLL, CHARLES SPYR. 

